Acceleration sensors are used for example to measure the acceleration of the movements of vehicles. Acceleration sensors are spring-mass systems in which, when accelerations occur, at least one seismic mass is deflected relative to the substrate, against a reset force that is capable of being modified with the deflection. The design of acceleration sensors is based on the fact that they have both electrodes connected to the seismic mass and electrodes connected to the substrate, which may be fashioned as plate capacitors. During the deflection caused by acceleration, a change in the electrical capacitance can be measured between the electrodes connected to the substrate and the electrodes connected to the seismic mass. The change in the capacitance is acquired and evaluated using circuitry and makes it possible to calculate the occurrent acceleration. For the manufacture of the acceleration sensors, the mass and the springs are etched from silicon, for example using a photolithographic process. In order to obtain a self-supporting structure, a layer underneath the mass, for example of silicon dioxide, is also removed by etching.
Such an acceleration sensor is discussed in German patent document DE 10 2006 033 636 A1. The acceleration sensor includes a substrate, a center web situated over the substrate, a first and second lateral web situated at the sides of the center web, and a seismic mass, electrodes being fashioned on the seismic mass and on the first and second lateral web. In addition, the acceleration sensor has anchors that are situated under the center web and under the first and second lateral web, and that connect the center web and the two lateral webs to the substrate.